As described in Patent Document 1, there has been a method including placing a laminated core having core sheets caulked and laminated between a resin injection mold (an upper die or a lower die) and a supporting mold (a lower die or an upper die) (also referred to as a core body), discharging a resin by a plunger from a resin reservoir pot of the resin injection mold, and resin-sealing permanent magnets (including one that is not magnetized; the same applies in the following) placed in magnet insertion holes of the laminated core.
Further, as described in Patent Document 2, there is also a method including placing a middle plate (also referred to as a dummy plate or a cull plate) between a laminated core and a resin injection mold, and injecting a resin into a magnet insertion hole of the laminated core through a runner from a resin reservoir pot of the resin injection mold.